背景切换器？

I’m trying to create a background switcher, but I’m unsure as to what approach I should take. I’m trying to avoid multiple style sheets, so should I maybe use uri segments and a redirect to referrer? or use a form for each item and make the anchor for each thumbnail the submit button sending a hidden id to php?

Also I’m aiming to store some meta data for each background in a db, so I could pull information such as the artist or the name of the background from the db.

I’m just stuck, can someone give me a nudge? Please and thank you [:

Here's what I used.

<?php
        $backgrounds = array();
        foreach(scandir('images/') as $file)
          if(strpos($file, '.png')||strpos($file, '.jpg')||strpos($file, '.jpeg'))
            array_push($backgrounds, $file);
        shuffle($backgrounds);
?>
<img id="bg" src="images/<?php echo $backgrounds[0]; ?>" />

And the CSS:

#bg{
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  position: absolute;
}

This creates a scaling background which is completely random among all the images in the "images" folder.

I'm off to school, so I don't have time to modify it for your purposes, but maybe this will give you the nudge you've been looking for.